The formation of mixed disulfides in the control of metabolism in lean mice (C57B1/6J) will be contrasted with the apparent lack of such control with obese and diabetic mice (ob plus/plus ob and db plus/plus db). Control enzymes in glycolysis and gluconeogenesis in liver and muscle will be assayed under various conditions with and without the addition of reduced and oxidized glutathione. Crude cytosolic fractions and partially purified enzyme fractions will be studied to determine whether or not the mechanism is direct or indirect. Cytosolic enzymes will also be separated and assayed directly on polyacrylamide gels. The effects of treatment of C57B1/6J mice with streptozotocin and insulin will be documented.